In vitro Probiotic Potential and Anti-cancer Activity of Newly Isolated Folate-Producing Streptococcus thermophilus Strains
- 2018-09-19
- Frontiers in Microbiology 9
- A. Tarrah
- J. de Castilhos
- R. Rossi
- V. Duarte
- D. Ziegler
- V. Corich
- A. Giacomini
- PubMed: 30283428
- DOI: 10.3389/fmicb.2018.02214
Abstract
Most probiotic strains commercially available today are lactic acid bacteria. Within this functional group, Streptococcus thermophilus is a thermophilic species widely used as starter culture for a huge number of dairy products. Besides being rapid acidifiers, many S. thermophilus strains are able to produce and release folate during growth but, unfortunately, they are seriously impaired during passage through the human gastrointestinal tract. In this work, we studied eight S. thermophilus strains isolated from dairy environments in Italy, which already had shown good technological properties, to evaluate their possible probiotic potential and cytotoxicity against cancer cells in vitro. All strains were also evaluated for some health-related properties such as susceptibility to most common antibiotics, hemolytic activity, resistance to simulated gastrointestinal conditions, bile salts hydrolytic activity, production of folate, adhesion to HT-29 human colorectal adenocarcinoma cells and cytotoxic activity against cancer cells and production of biogenic amines. Results revealed that two fast acidifying S. thermophilus strains were found to possess in vitro probiotic properties along with anticancer activity and production of folate. These properties resulted similar and, in some cases, superior to those of Lactobacillus rhamnosus GG, a well-known commercial probiotic strain. These findings encourage further in vivo studies to evaluate the actual health benefits of these strains on the human host.
Keywords: Streptococcusthermophilus; cytotoxic activity; folic acid production; gastrointestinal resistance; hemolysis; probiotic.
Research Insights
| Supplement | Health Outcome | Effect Type | Effect Size |
|---|---|---|---|
| Streptococcus thermophilus MAK34S24T | Enhanced Gut Health | Beneficial | Moderate |
| Streptococcus thermophilus MAK34S24T | Increased Anticancer Activity | Beneficial | Moderate |
| Streptococcus thermophilus MAK34S24T | Increased Folate Levels | Beneficial | Moderate |
| Streptococcus thermophilus SEBiotic | Enhanced Probiotic Activity In Vitro | Beneficial | Large |
| Streptococcus thermophilus SEBiotic | Increased Folate Levels | Beneficial | Moderate |
| Streptococcus thermophilus SEBiotic | Reduced Cancer Activity | Beneficial | Large |
| Streptococcus thermophilus ST-21 | Enhanced Gut Health | Beneficial | Moderate |
| Streptococcus thermophilus ST-21 | Increased Anticancer Activity | Beneficial | Moderate |
| Streptococcus thermophilus ST-21 | Increased Folate Levels | Beneficial | Moderate |
| Streptococcus thermophilus ST1447 | Improved Gut Microbiota | Beneficial | Moderate |
| Streptococcus thermophilus ST1447 | Increased Anticancer Activity | Beneficial | Moderate |
| Streptococcus thermophilus ST1447 | Increased Folate Levels | Beneficial | Moderate |
| Streptococcus thermophilus VPro 23 | Enhanced Folate Synthesis | Beneficial | Moderate |
| Streptococcus thermophilus VPro 23 | Improved Gut Microbiota | Beneficial | Moderate |
| Streptococcus thermophilus VPro 23 | Increased Anticancer Activity | Beneficial | Moderate |
| Streptococcus thermophilus Y08 AF | Enhanced Gut Health | Beneficial | Moderate |
| Streptococcus thermophilus Y08 AF | Increased Anticancer Activity | Beneficial | Moderate |
| Streptococcus thermophilus Y08 AF | Increased Folate Levels | Beneficial | Moderate |